Magic Tree bookstore co-owners Iris and Victor Yipp were on a ski vacation in Whitefish, Mont., recently, when they discovered one of Frank Lloyd Wright's last works. The 1961 building, which changed over the years from a medical facility to a bank to (currently) a law office, appears to have a "pagoda effect."

"This is pretty different from the homes and Unitarian Church he designed in Oak Park," Iris said.